Color Blind

Know what hues birds and animals can pick out so you can stay hidden.

For decades, scientists examined eye structure to determine whether wildlife could see color. The common belief was that big game could not see color, so your blaze orange hat and vest would blend into their gray-toned world. However, camo was considered critical for turkey and waterfowl hunting because turkey, ducks, and geese were thought to have keen color vision.

In the past 10 years, new research techniques have revealed much more about wildlife vision. For example, we now know that deer can discriminate between blue and yellow-green, and it turns out that they can see orange and red too!

“Anatomically, we know that deer can discriminate longer wavelengths (red and orange) from medium wavelengths like green, but our understanding is incomplete,” says Scott Werner, research wildlife biologist at the U.S. Department of Agriculture’s National Wildlife Research Center in Fort Collins, Colorado.

Much of the research on what wildlife sees has focused on the ultraviolet (UV) spectrum. To humans, when light in the UV spectrum is present, blues, greens, and reds appear brighter. We don’t actually see in the UV “color” range – but many birds do. Birds see in four classes of color: blues, greens, reds, and shorter UV wavelengths. Primates (including humans) see only blues, reds, and greens.

“Birds respond differently in the presence or absence of UV wavelengths,” says Werner, who points to experiments in which Canada geese and wild turkey responded behaviorally to UV feeding cues.

And then there are cervids such as white-tailed deer. They can see differences in the color spectrum from blue to yellow-green, and they can distinguish orange and red. But how they interpret those colors in their environment is the big question.

“The greatest disservice I can do is  to say deer are ‘color blind’ or that they cannot see orange,” says Werner. “They can. Although deer can visually detect the color orange, it is the brightness and patchiness of the clothing worn by hunters and not the exact color per se that most likely draws a deer’s attention.”

How much you move around is also a factor. According to Werner, wildlife tend to catch movement with their peripheral vision, then turn toward  the movement to identify it using their binocular vision (focusing on the cause of the movement with both eyes at once).

Camo patterns on clothing can help hide you. “If there are fine color specks all around you, like lots of leaves in the fall, you need to mirror that,” advises Werner. “If the background is uninteresting, like on the prairie, it’s okay to wear solid pants and an old-style checked shirt.”

What about wearing blaze orange or pink? Hunting garments in those colors are still important for your safety – so other hunters can see you. And if you sit still (and downwind), the whitetails won’t pay attention.

Fish Eyes

Understand what fish see underwater to increase the odds of hooking one.

Fishing can be a confounding sport. One day a lure works and the next day it doesn’t. It might be due to the way fish see it, which can vary based on the amount of daylight, how deep the fish is, and the angle from which the fish is looking at it.

“To form an image, a fish eye needs light and contrast,” says Andrij Horodysky, PhD, assistant professor of marine and environmental science at Hampton University. (He’s also a professional fly tyer.) “Light allows a fish to see the outline of its food. Contrast allows it to pick it out from a background. Many fish are mobile predators. They’ll change the direction they face relative to the sun to improve contrast.”

According to Horodysky, you need two kinds of flies or lures: light-colored ones if the fish are looking at a dark background and dark ones if the back- ground is light. Dark backgrounds could include low-light situations or when you’re standing with your back to a tree-lined stream bank. A light background might be when a fish is looking straight up toward the surface on a sunny day. Babbling water (riffles) also create a light background for fish.

Specific colors matter most near the surface and when the fish gets close.

“When a trout on the bottom looks up at a fly, it’s not yet keying on color,” says Horodysky. “As it gets closer, it starts to see some color because the object is larger and there’s less water between it and the fish… Think of water as a filter. The greater the distance, the more an object becomes dimmer and bluer.”

For this reason, when fish are feeding at the surface, color is more important than when fish are three or more feet underwater. The deeper the water, the more important silhouette and size become.

Horodysky offers these tips for the best lures for common fishing situations.

• Debris floating in the water: The fly/lure needs to look different than the debris particles that fish are used to ignoring.
• Cloudy day: Dark flies/lures have more contrast against the dull, white surface of the water. Think silhouette!
• Green or brown-stained water: Fish can’t see as far or as clearly. Pick flashier subsurface flies/lures.
• Trolling: Color matters when fish look across the water at the fly/lure rather than up at it.
• Dawn and dusk: Light is changing quickly. Contrast matters most. Large streamers and lures are better.
• Red hooks, red tones  in  flies/ lures: Red looks black or gray to fish until the fish is close because fish primarily see in green and blue tones. (Red mainly attracts the angler to purchase the fly or lure.)
• Popular fishing spots: Match closely what fish are eating. They’ve seen everything.
• Remote (hike-in) fishing spots: Fish are less shy, but you need to catch their attention. Emphasize contrast to help them see the fly/lure from farther away.

“What most trout eat is brown and 5/8-inch long or shorter,” says Horodysky. In other words, small and non-flashy. What enables fish to see their prey is contrast. “Unless it’s a situation in which you need to match exactly [what the fish are eating], all you need to know is how it’s viewing your fly or lure against the background.”